Medical electrodes for introducing and discharging electric currents into and from the human or animal body have been known for a considerable length of time. A very wide range of production methods also exists in this field, in which connection it has become increasingly important in recent years to produce electrodes that are as small and light as possible. In the field of diagnostic electrodes there is also increasingly a desire to allow evaluations that are uninfluenced as far as possible by electromagnetic radiation and other sources of interference. To this end, in addition to corresponding electrode designs shielded cables in particular are used. These shield the detected signal against interference by electromagnetic radiation and possibly also protect the patient.
In order in particular to produce the electrode head—with which the medical electrode is attached to the body—as simply and thinly as possible, it is known from the prior art to apply at least individual layers by a printing method. For example, US 2010/0030167 A1 shows an electrode with electrically conductive rings and a further shielding layer as second electrically conductive layer. This second electrically conductive layer can be printed onto the electrode.
According to WO 2009/007877 A2 an electrode head is principally described, in which a conductive ink is applied to the surface of a film layer. It can also be envisaged to print a dielectric layer over a base conductor.
Furthermore it is known from DE 699 23 680 T2 that in the case of an electrode a sealing layer (in the chemical sense) of a silver alloy ink is printed over a circuit of conductive ink.
Furthermore DE 40 91 800 C2 shows a biosignal electrode onto which a two-ply electrically conductive layer is printed.
In the technical field of the feed line to the electrode head, shielded and unshielded cables of round cross-section are known. For a connection that integrates the electrode head into the shielding, the connections and associated plugs either have to be configured in a relatively complicated manner, as is illustrated in EP 1 569 551 B1, or the plug additionally has to be designed as a shield overlapping the electrode head, which means that this region is heavy and inflexible and moreover is qualitatively inferior to a shielding integrated into the electrode.
The disadvantage therefore is basically the fact that the production of a medical electrode with an electrode head and integrated, unshielded and round cable feed line is carried out in a series of steps that are always very complicated, expensive and normally completely separate from one another, involving to some extent manual assembly, which is why the processes for producing such medical electrodes are very inefficient.
These difficulties—and therefore the costs—are magnified especially if only one electrode with a shielded electrode head and integrated shielded cable feed line is to be produced, which is why such single-use products are hardly ever found on the market.
Furthermore, as regards the feed line to the electrode head of a medical electrode it is known from U.S. Pat. No. 4,353,372 A that the electric conductor on the feed line as well as the conductor in the region of the connecting plug are printed as a conductive layer.
From U.S. Pat. No. 4,442,315 A and US 2007/0299471 A1 in each case medical electrodes with an electrode head and feed line are known, in which the shielding layers and insulating layer can be printed on in the region of the feed line. With these printed-on shielding layers there is however no complete shielding of the electric conductors, so that electromagnetic radiation or other sources of interference can influence the signals fed through the electric conductor in the feed line.